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Independent practice 1

1.) 1 + x \ x - 2 = 4

2.)
[tex]5x \geqslant 2 \2x - 1[/tex]
3.) f(x) x² -7 \ x + 2 -3
4.) x+2 \ x-2 = y + 3; HINT y is representative by f(x)
5.) x+1 \ 2 <
[tex] \sqrt{x + 3} [/tex]




Sagot :

Answer:

1)x+11+x−22=x+44

2)22x+1=2x−1⇒4(2x+1)=4x2−4x+1(squaringbothside)⇒4x2−12x−3=0∵b2−4ac=(−12)2−4.4.(−3)=192>0∴xhas2distinctrealrootsi.e,x=2a−b±b2−4ac=23±23

3)2x2−5x+7=0

x=2a−b±b2−4ac

x=45±25−4(2)(7)

x=45±−31

Hence 2x2−5x+7=0 does not have roots as 1,2,3.

Hence f(x) is continuous for all x.

4)x+2+y+3+(x+2)(y+3)=39

(x+2)2+(y+3)2+(x+2)(y+3)=741

Let  x+2=p,y+3=q.

p+q+pq=39⟶I

p2+q2+pq=741⟶II

⟹p+q−39=−pq

Squaring on both sides:-

⟹p2+q2+1521+2pq−78p−78q=pq

⟹p2+q2+pq=78p+78q−1521⟶III

Subtracting II  from  III

78p+78q−1521−741=0

78p+78q−2262=0

p+q=29⟶IV

From  I

pq=10

pq=100⟶V

p−q=(p+q)2−4pq

=841−400

=441=21⟶VI

Adding  IV  and  VI

2p=50

p=25,q=4

x+2=25,y+3=4

x=23,y=1

5)

x−11+x−22=x−33

(x−1)(x−2)x−2+2(x−1)=x−33

(3x−4)(x−3)=3(x−1)(x−2)

3x(x−3)−4(x−3)=3[x(x−2)−1(x−2)]

3x2−9x−4x+12=3[x2−2x−x+2]

3x2−13x+12=3x2−9x+6

4x=6

x=46=23

HEHEHHE PA BRAINLIEST PO